Employee Benefit Plans - Additional Information (Detail) (USD $)	3 Months Ended
Mar. 29, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Intrinsic value of options exercised	$ 500,000
Discretionary contributions of plan	25.00%
Percentage of contribution by eligible participants	4.00%
Maximum contribution per participant	$ 1,000
Defined contribution plan description	This plan allows participants to contribute up to the applicable Internal Revenue Code limitations under the plan. Prior to 2009, Harmonic made discretionary contributions to the plan of 25% of the first 4% contributed by eligible participants, up to a maximum contribution per participant of $1,000 per year. Harmonic's contributions were suspended from 2009 through 2012, but have been renewed, on the same basis, for 2013.

- Definition

Description of the terms and benefits provided by the employer's defined contribution plans. A defined contribution plan provides benefits in return for services rendered, provides an individual account for each participant, and has terms that specify how contributions to the individual's account are to be determined rather than the amount of benefits the individual is to receive. Under a defined contribution pension plan, the benefits a participant will receive depend solely on the amount contributed to the participant's account, the returns earned on investments of those contributions, and forfeitures of other participants' benefits that may be allocated to such participant's account. A description of the plan(s) including employee groups covered, the basis for determining contributions, and the nature and effects of significant matters affecting comparability of information for all periods presented.

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